3115 white screen

MDY

New member
This board power with chime and TB image is OK.
But on LVDS screen no video, white screen.

I checked and L9004 was bad. I replaced it and no no white screen anymore. Now dark screen but no video, no backlight. If I remove L9404 I have white screen again.
LCDVDD, LCD_F, CLK and DATA are at 3.3V
LCDBKL - 25V

I tested this screen on working board and screen is ok.
LVDS connector from pin8 to pin 18 compared with another board I have same value 5M en all data pins.

Any idea what to check next?
 
Last edited:

dukefawks

Administrator
Measure all LVDS lines on diode mode. Check if L9080 is not damaged. Also installing L9004 should not affect backlight...
 

MDY

New member
1-0.00
2-0.642
3-0.642
4-0.363
5-0L
6-0.668
7-0.668
8-0.716
9-0.717
10-0.00
11-0.716
12-0.717
13-0.00
14-0.718
15-0.718
16-0.00
17-0.716
18-0.717
19-0.00
20-0L
21-0.602
22-0.602
23-0L
24-0.642
25-0.643
26-0.641
27-0.639
28-0.640
29-0.640
30-0L

Red on ground.
 

MDY

New member
It is not affecting the backlight. Just wthout L9004 I have only backlight, and after installing L9004 I think I still have backlight but TFT is already powered and I see dark screen.
 

dukefawks

Administrator
You think you have backlight? Is it hard to see the Apple logo lighting up?

Inspect connector for damage. Measure all LVDS lines at the end of a known good LCD cable. Also check if power after L9004 is 3.3V and not too low.
 
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